Increasing numbers of women of childbearing age in the Southeastern U.S. are becoming infected with HIV. If these women become pregnant and are relatively healthy with no signs or symptoms of AIDS, ACTG 076 ( AIDS Clinical Trials Group) dramatically demonstrated that a three-part regimen of zidovudine (ZDV) administered to the mother orally during pregnancy, intravenously during labor, then orally to the infant, resulted in a reduction of transmission of HIV to the infants from 25% in the control group to 8% in the group receiving the study treatment. The study presented here in ACTG 185, A phase III randomized, double-blind, controlled study of hyperimmune anti-HIV intravenous immune globulin (IIIVIG) in prevention of maternal-fetal transmission in women and newborns receiving zidovudine (ZDV), conducted as part of the multicenter pediatric ACTG, and was designed to determine if hyperimmuneglobulin to HIV (HIVIG) given to pregnant women and infants, in addition to the ZDV regimen used in ACTG 076 would reduce the transmission of HIV to infants in sicker mothers than those participating in ACTG 076. In this study all women enrolled had CD4 counts <500 cells/mm3 or CDC defined AIDS and all received ZDV. The IVIG administration was double blinded, randomized and placebo controlled, using routine IVIG as the control for the study treatment. Data analysis is being performed by the central study and statistical office and the study was periodicallly reviewed for safety by the Data Safety and Monitoring Board of the PACTG.